Muffler.



No 871,775. PATENTED NOV. 26, 1997.

F. O. BLANGHARD & E. B.'GROGKE R. I

MUFFLER.

APPLIUATION FILED JULY 22. 1907.

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No. 871,775. 7 I PATENTED NOV. 26, 1907.

F. 0. BLANGHARD & B. B. OROGKER. 7

MUFFLER.

APPLIUATION FILED JULY 22. 1907.

2 SHBETS-SHBET 2. 3

CONNECTICUT.

Fro v FREDERICK C. BLANCHARD AND ERNEST B. OROGKER, OF .BRIDGEPORT,CONNECTICUT,

ASSIGNORS TO THE CONSOLIDATED SAFETY VALVE, COMPANY, A CORPORATION OFMUFFLER."

i tnam filed July 22.1907. Serial No. 384.898.

'Connecticut, havo'invented new and useful Improvements in Mufflers, ofwhich the followig is a specification.

Mg invention relates to the construction of mufflers such as areemployed to deaden the noise of exhausting steam or other gases,andconsists in improvements in the muffling devices, whereby theefficiency of mufflers is improved and their effective operationfacilitated. I In particular, I have contrived my improved mufi'ler forsteam-escape and safety valves, though my improvements are adapted toother situations and may be used for muflling purposes Wherever it isdesired to suppress the'noise of escaping gases.

I am aware that safety valve and other mufilers have been designed andmanufactured, wherein several contrivances for breaking up, baffling,and distributing the steam of escaping gas have been suggested oremployed. Baflie plates, inclosed in a shell or drum through which thegases pass to the atmosphere, are an old device, and transversebafileplates have been employed in which a multitude of perforationsperformed the muflling function. I am informed also, that mufflers usingrolls or cylinders of woven wire fabric, others using a mass of metalchips or lathe turnings, others using a mass of small fragments ofstone,

glass or other solid material, and still others using coiled springs,spirally coiledin the mufiler drum, have been suggested or used, and Iam personally familiar with some of the practices mentioned. While anyor all of these muflling devices serve in some measure to perform theessential function of breaking up and baffling the stream of escapingsteam or other gas, they do not, so far as I am'aware, serve the purposeas well as is desirable. The irregularities of coiled wire springs, orwoven wire fabric, are not sufficiently pronounced to obtain the besteffect, and mufflers composed of masses of fragments are liable tobecome matted and practically impervious in some port-ions, leavingother portions much too free and unob- Specification of Letters Patent.

.tion of the instrument as a whole. observed, in experiments withbroken-fragment mufflers, that the fragments where- Patented 1\'l'ov.?26, 1907.

structed to perform the muffling function properly, as they leave thesteam or other gases free to follow a course of least resistance, whichis 'recisely what a muffler should not do. n the other hand should amuffler be too closely restricted in its subdivided passages, it willrestrict theescape of gases unduly, and possibly interfere, by creatingback pressure, with the proper Iopleraave with the muffler she'llis'filled become chipped and comminuted by the agitation produced by ablast of gas, and deliver uantities of dust and grit, produced by thereaking up of the fragments in the muffler shell. Thus, little by littlethe muffler so constructed becomes deteriorated and more and more in-.efficient. I

'I have determined by experiment and trials, that essentially the bestinstrument for retarding and breaking up a stream of gas, is a flatplate, since the effect of a plate on the impinging stream is toexplode" it, so to speak, by spattering it in all directions.

I have further determined that if a large number of small separatedbaflle plates are opposed to the passage of the stream of steam or otherescaping gas, so that the gas must inevitablyimpin'ge repeatedly againstthe surfaces of these plates and be obliged to find its way over theedges thereof the effect is still further improved. I believe that thisimprovement in the muffiing effect in case a multitude of small thinbaffle plates is employed is due to the fact that not only is the streamof gas scattered by im inging u on safety valve muffler; Fig. 2, is adetail in ele-- vation, showing the form of muffiing device whichI-employby preference; Fig. 3, isa side view of thedetailshown in Fig,2; Figs- 4, 5 and 8 are elevations showing the details;

In Fig. 1, A represents a safety valve casing in which the valve B isseated, the valve 1 being held to its seat in the usual manner by thespring E. The upper part D is mounted in the usual Way on t e upperportion of the valve casing from which the segmental pas sages 0 leadand areinlets to the muflier space. The 'mufller s ace is inclosedbetween the outer shell and the inner cylind ncal portion of the topcastingjD this shell 1 being. provided with an upper inturned flange G,which is filled with erforations g; the shell is seated at the top ofthe casting D, and at the bottom of the outer edge of the flange or mm dwhereto the shell is secured into-place, as at n.

My 1111 roved muflling contrivance is shown at m Fig. 1, and iscontained within the muffler space between the top casting D and shellF.

While I have shown in Figs. 1. 2 and 3 the form of muflling device whichI have selected; by preference, the principle of constructlon is perhapsbetter illustrated by Flgs. 4 to 9 inclusive, which show alternate modesof constructing my improved mufiling device. In Fig. 4, for instance,there is shown a fragment of a thin metal sheet in whlch seml-circularholes t" are cut, leaving the material uncut along the diameter of eachof the holes so that fins or shelves 'i are formed standing out" at.anangle from the sheet I. TlllS angle may be a right angle or any otherangle desired; I prefer to turn the sald shelves out atsubstantiallyright angles for the reason that I believe the ifiufllingeffe, ct 1s best attained in this manner. In Figs. 4 and 5 the shelves'5 are shown as lying 1n planes parallel to the upper edge of the sheetI, but if desired the shelves i may be formed so that they stand not onlat an angle to the general surface of the siieet but are also slightlyinclined in relation to the upper edge, as shown in Fig. 6 or as shownin Fig. 8', the shelves 1) may some of them be inclmed 1n one directionand others in the opp os1t'e direction. tioned construction and, asshown in Fig. 9,

prefer to stagger the holes i; and to make the inclination of theshelves & alternate from row.to row horlzontally. In no case, however,do I consider it advisable to incline the shelves much more than 30degrees from the upper edge of the sheet.

I take a sheet I of such height as to extend from top to bottom of thespace within the muffler shell and of such length that when the plate isrolled 'into a helix so that the shelves of'feach' turn touch the backof the plate at the next turn or convolution, the entire helix willsubstantially fill the muffler space.' In punching the holes '1'. andforming I prefer the last men' the shelves i it is desirable to make asmany perforations and shelves as the material of the sheet I willaccommodate, because the larger the number of shelves the moreefl'ctively will the muflling function be performed and the larger thenumber of perforation-2 the more freely will the stream of gas passthrough the entire mufiler.

In Figs. 2 and 3 I have shown in plan and j edge view, res actively, afragment of socalled expandec metal, which by virtue of its.

peculiar, construction brings the aggregate Y aperture surface to amaximum, and ikewise presents the largest possible number of laterallyprojecting fins or shelves. By preference, therefore, and forconvenience in manufacture I select for my muflling device a helicallyrolled sheet of expanded metal and have shown such a sheet at I inFig. 1. The expanded metal provides by its mesh the requisite largenumber of baffling shelves which stand out at an an le closelyapproaching a right angle from the sheet as a whole and which affordsalso the largest possible measure of apertures through the sheet.

Steam or other escaping ases passin from the inlet of the muffler shelas at C in .ig. 1, to the outlet, thereof as provided by theperforations g; which scatter the gas streafn in every direction andwhich by reason of their thin sharp edges and fiat up er surfaces alsobreak the gas up into a mu titude of eddies and by this mode ofoperation effectively deaden the noise which otherwise would be made bythe escaping gas. 7 The stream of steam or other gas is as a wholesubjected to so little interruption by this mufiling device that noappreciable back pressure is created th ere-by.

Mechanically considered the muffling device shown and described has alsothis advantage that while abundantly perforated it is nevertheless arigid and continuous sheet which resists any tendency to alteration inthe size 01" distribution of the apertures.

'What I claim and desire to secure by Letters Patent is:

In a mufllena shell provided with an inlet and an outlet and a mufllingclement, inclosed in and substantially filling the shell, consisting oflayers of apertured sheet metal laid. parallel to the course of gasespassing from the inlet to the outlet and. formed with shelves standingout at an'angle from the layers of sheet metal.

2. In a muffler, a shell provided with an inlet and an outlet and amufl'ling element, inclosed in and substantially filling the shell,consisting of layers of apertured sheet metal laid parallel to thecourse of gases passing from the inlet'to the outlet and formed withshelves standing out at an angle from the sheet metal layers, theshelves also inclined to the axis of the shell.

3'. 111's muffler, a shell provided with an inlet and an outlet and amutiling element, inclosed in and substantially filling the shell, andconsisting of a helically coiled apertured metal sheet formed withshelves standing out at an angle from the sheet, the axis of thecoil'substantially parallel to the course of the gases passing from theinlet to the outlet.

4. In a muffler, a shell provided with an inlet and an outlet and aIn'uflling element, inclosed in and substantially filling the shell,

- and consisting of a helically coiled apertured metal sheet formed withshelves standing out at an angle from the sheet, the axis of the coilsubstantially parallel to the course of gases passing from the inlet tothe outlet, the saiil shelves also inclined to the axis of the col 5. Ina muhhrr, a shell provided with an inlet and an outlet and a mufllingelement, inclosed in and substantially 'Iilling the shell, consisting oflayers of apertured sheet metal laid parallel and formed with shelvesstanding out an angle from the sheet metal layers.

6. In a muffler, a shell provided with an inlet and an outlet and amuifling element,

inclosed in and substantially fillin the shell,

consisting of layers of a ertured s eet metal 4 laid parallel and formewith shelves standing out at angle from the sheet metal layers, the saidshelves also inclined to the axis of the shell. I

7. In a mufller, a shell provided with an inlet and anoutlet and amuflling element inclosed in and substantially filling the shell,consisting of parallel layers of expanded metal.

8. In a mufiier, a shell provided with an inlet and an outlet,'a'mufliingelement inclosed in and substantially filling the shellconsisting of a helical coil of expanded metal,

the axis of" the coil parallel to the course of gases from the inlet tothe outlet of the shell. Signed by us at Bridgeport, Fairheld county,Connecticut, this 12th day of July FREDERICK (l. BLANCIIARI). ERNEST B.CROCKER.

VVtnesses:

W. R. CLARKE, WM. R. S'ruonn.

